Imports System

Public Module Module1

    Public Sub Main()

        Dim i, j, n As Integer

        Console.Writeline("Input a number")

         n = Console.ReadLine()

        Do while n<0 

            console.WriteLine("Please input a positive number")

            n=console.ReadLine()

        loop

        For i = 1 To n

            For j = 1 To i

                Console.Write("X")

            Next

        console.Writeline()

        Next

​

​

    End Sub

End Module